Machine vision systems find use in a variety of applications, with area monitoring representing a prime example. Monitoring for the intrusion of objects into a defined zone or volume represents a key aspect of “guarding” applications, such as hazardous machine guarding. In the context of machine guarding, various approaches are known, such as the use of physical barriers, interlock systems, safety mats, light curtains, and time-of-flight laser scanner monitoring.
While machine vision systems may be used as a complement to, or in conjunction with one or more of the above approaches to machine guarding, they also represent an arguably better and more flexible solution to area guarding. Among their several advantages, machine vision systems can monitor three-dimensional boundaries around machines with complex spatial movements, where planar light-curtain boundaries might be impractical or prohibitively complex to configure safely, or where such protective equipment would impede machine operation.
On the other hand, ensuring proper operation of a machine vision system is challenging, particularly in safety-critical applications with regard to dynamic, ongoing verification of minimum detection capabilities and maximum (object) detection response times. These kinds of verifications, along with ensuring failsafe fault detection, impose significant challenges when using machine vision systems for hazardous machine guarding and other safety critical applications.